In conventional cameras, a film cartridge is loaded into a loading chamber. Film in the film cartridge is manually or automatically loaded into the camera. Images are then recorded on the film after which the film is rewound into the film cartridge. A door covering the loading chamber is opened and the film cartridge is removed so that the film can be processed.
In traditional 35 mm cameras, the film cartridge is loaded into the loading chamber in a direction perpendicular to the cartridge spool. More recently, cameras have been developed in which the film cartridge is loaded in a direction parallel to the cartridge spool or end first. Such a camera is disclosed in U.S. Pat. No. 5,155,514.
In U.S. Pat. No. 5,155,514, a film cartridge is pushed down into a loading chamber. By pushing the cartridge into the chamber, an end of the cartridge contacts a sloped face of a lock lever, causing the lock lever to be moved to the right. The cartridge is pushed into the chamber against a spring. Once the cartridge is completely in the chamber, a spring forces the lock lever to the left, thereby retaining the cartridge in the chamber against the force of the spring. A cover member is then moved to the left to cover the loading chamber.
When it is desired to remove the film from the loading chamber, the cover member is moved to the right against a spring. The movement of the cover member causes the lock lever to move to the right against the spring. When the lock lever is moved far enough to the right, a portion of the lock lever disengages the upper surface of the cartridge, allowing the cartridge to move out of the loading chamber under the influence of the spring.
A problem with the mechanism in the above-described patent is that when the lock lever is moved to the right, releasing the cartridge, there is nothing further to prevent the cartridge from moving out of the loading chamber. If the camera is oriented so that the loading chamber is in a near horizontal position or upside-down, the film cartridge may be ejected completely out of the loading chamber by the spring. If the operator is not prepared to catch the ejected film cartridge, the cartridge may fall and strike a hard surface, thereby becoming damaged and possibly ruining the film contained therein.
Commonly assigned U.S. Pat. No. 5,430,515 overcomes this problem by including a retainer the engages the film cartridge upon unloading of the film cartridge so that partial unloading is achieved and full unloading is prevented. Once in the partially unloaded position, the film cartridge is manually engaged by the user for exerting enough force to overcome the bias of the retainer for permitting the film cartridge to be totally unloaded.
Although the presently known and utilized systems for unloading the film cartridges are satisfactory, it is always desirable to combine camera features for simplicity and efficiency. More specifically, the prior art cameras do not link the unloading of the film with other camera features for automatically performing an operation that is needed upon loading and/or unloading of the film.
Consequently, a need exists for a camera overcoming the above-described drawbacks.